DETERMINATION OF ORGANOCHLORINE PESTICIDE RESIDUES IN GLYCYRRHIZA URALENSIS FISCH. BY CAPILLARY GAS CHROMATOGRAPHY WITH ELECTRON CAPTURE DETECTOR(CGC-ECD)

AIM　To determine 15 organochlorine pesticide residues in Glycyrrhiza uralensis Fisch. by capillary gas chromatography with electron capture detector(CGC-ECD). METHODS　Samples were extracted with mixed solvents by ultrasonic, then cleaned up by a column packed with Florisil. The capillary column was DB-5(15 m×0.32 mm×0.25 μm); injector temperature was 240℃; detector temperature was 320℃; the column temperature program: initial 100℃(hold 0.5 min), rate of 20℃.min^-1 to 210℃(hold 0.5 min), rate of 8℃.min^-1 to 240℃(hold 5 min). The column head-pressure was 58.84 kPa. The pesticide residues were calculated by external standard method. RESULTS　The average recoveries and RSD ranged from 74.7% to 119.2% and 0.7% to 18.9% respectivily, at three spiked mixed organochlorine pesticide levels. CONCLUSION　The method is easy in operation and has good separation and repeatability.